Integrated Motor-Gear Box Wheel Hub Drive

ABSTRACT

A monorail vehicle includes a chassis supporting a vehicle body, that includes a passenger floor and at least one side wall, and an electrical motor supported by the chassis. A drive wheel is coupled to a rotor of the electric motor with a rotation axis of the drive wheel substantially coaxial with an axis of the rotor. Portions of the drive wheel and the electric motor are positioned on both sides of an imaginary plane extension of the passenger floor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This application relates generally to a monorail train includingmonorail vehicles and, more particularly, to drive units (or propulsionunits) utilized to propel said monorail train or vehicle along a rail.

2. Description of Related Art

Prior art monorail trains, including monorail vehicles, include driveunits or propulsion systems wherein the drive wheels and the drivemotors were operatively coupled together, by a suitable gearingarrangement, with their respective rotation axes transverse orperpendicular to each other. Problems with such prior art arrangementsinclude reduced passenger space in the interior of such vehicles and/oran increase in the overall height of the monorail vehicle to accommodatethe drive unit or propulsion system.

SUMMARY OF THE INVENTION

Disclosed is a monorail vehicle comprising: a chassis coupled to a bodyof the monorail vehicle; a drive unit coupled to the chassis, the driveunit comprising an electric motor and a planetary gear assemblyrotatably coupled to the electric motor, the planetary gear assemblycomprising at least 3 planet gears coupled between a sun gear, which iscoupled to a rotor of the electric motor, and a ring gear surroundingthe planet gears, the planet gears rotatable within the ring gear (orthe planet gears fixed and the ring gear rotatable) in response torotation of the sun gear by the electric motor; and a rim assemblycoupled to the planetary gear assembly for rotation thereby, the rimassembly including a pair of side-by-side rim sections adapted tosupport a pair of wheels side-by-side for rotation about a rotation axisof the rim assembly that runs coaxial with a rotation axis of the rotorof the electric motor and a rotation axis of the sun gear, the rimassembly further including a hub that extends radially from the rotationaxis of the rim assembly and terminates on an interior surface of therim assembly, wherein one of the rim sections at least partiallysurrounds and rotates about the planetary gear assembly in response torotation of the rim assembly by the planetary gear assembly.

The electric motor can be AC motor. The AC motor can be a permanentmagnet AC motor. The permanent magnets can be disposed on the rotor.

The hub can terminate on the interior surface of the rim assemblybetween the pair of side-by-side rim sections.

The planetary gear assembly and the electric motor can be receivedwithin a housing that is coupled to the chassis, wherein the one rimsection rotates about a section of the housing that houses the planetarygear assembly.

A brake rotor can be coupled to an end of the rotor of the electricmotor opposite the sun gear.

An interior of the vehicle can define a passenger pathway that extendslongitudinally along one side of the vehicle between an interior surfaceof the vehicle body and the drive unit.

The electric motor can be disposed within a housing that is coupled tothe chassis. The housing can include fluid channels for allowing thepassage of a cooling liquid therethrough for removal of heat generatedby the electric motor.

Also disclosed is a monorail vehicle comprising: a chassis supporting anelongated vehicle body that includes spaced sides and a passenger floor,wherein a length direction, a height direction and a width (orside-to-side) direction of the elongated vehicle body correspond to X, Yand Z axes, respectively, of a Cartesian coordinate system, wherein theX and Y axes define an imaginary plane that bisects the vehicle body inhalf; a drive unit coupled to the chassis, the drive unit comprising anelectric motor and a gear assembly, the electric motor including a rotorthat has an axis that is disposed substantially parallel with the Zaxis; and at least one drive wheel coupled to the rotor via the gearassembly, each drive wheel having a rotation axis that is disposedsubstantially coaxial with the rotor axis, wherein the drive unit issupported by the chassis with the electric motor and at least part ofthe gear assembly residing entirely in one of the halves of the vehiclebody with at least portions of each drive wheel, the electric motor andthe gear assembly residing above a plane of the passenger floor of thevehicle body.

A portion of the passenger floor can be disposed between one side of thevehicle body and the portions of each wheel, the electric motor and thegear assembly.

The electric motor can be a permanent magnet AC electric motor. Theelectric motor can be liquid cooled.

The gear assembly can be a planetary gear assembly. The planetary gearassembly can have at least 3 planet gears coupled between a sun gear anda ring gear which surrounds the planet gears, wherein the sun gear iscoupled between the rotor and the planet gears such that the planetgears are rotatable within the ring gear (or the planets can be fixedand the ring gear can rotate) in response to rotation of the sun gear bythe rotor.

The vehicle can include a pair of drive wheels supported by a rimassembly which is coupled to the gear assembly by a hub of the rimassembly, wherein at least part of the rim assembly surrounds the gearassembly, which part of the rim assembly is rotatable about the gearassembly in response to rotation of the rim assembly by the motor viathe gear assembly.

The pair of drive wheels can have a common rotation axis. The rimassembly can include an individual rim or a pair of rim sections witheach rim section supporting one of the drive wheels. The rim assemblycan include the hub which extends radially from the common rotation axisand which terminates substantially at the intersection of the pair ofrim sections.

The vehicle can include a bogie coupling the drive unit and each drivewheel to the chassis.

Also disclosed is a monorail vehicle comprising: a chassis supporting avehicle body that includes a passenger floor and at least one side wall;an electrical motor supported by the chassis; and a drive wheel coupledto a rotor of the electric motor with a rotation axis of the drive wheelsubstantially coaxial with an axis of the rotor, wherein portions of thedrive wheel and the electric motor are positioned on both sides of animaginary plane extension of the passenger floor.

A gear assembly can be coupled substantially coaxially between the rotorand the drive wheel.

The gear assembly can be a planetary gear assembly that has a rotationalaxis coaxial with the axis of the rotor and the rotation axis of thedrive wheel. Portions of the gear assembly can be positioned on bothsides of the imaginary plane extension of the passenger floor.

The passenger floor can run or extend between a front and a rear of thevehicle body and in a space between the drive wheel and the side wall.

A bogie can couple the electrical motor and the drive wheel to thechassis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a monorail train including a first car and a partialsecond car, wherein the first car includes a phantom view of a pair ofbogies, with each bogie supporting a drive unit and drive wheels of themonorail vehicle;

FIG. 2 is a section taken along lines II-II in FIG. 1 showing the bogie,the drive unit, and a section of the drive wheels relative to the driveunit, in relation to an interior of the monorail vehicle and showing aspace on the passenger floor between the drive wheels and a side of themonorail vehicle;

FIG. 3 is a perspective view of the interior of the monorail vehicletaken along lines III-III in FIG. 1 showing a space on the passengerfloor between a shell, covering a bogie, a drive unit, and drive wheels,and an interior side of the monorail vehicle;

FIG. 4 is a partially cutaway view of one of the drive units shown inphantom view in FIG. 1; and

FIG. 5 is an isolated perspective view of some of the internalcomponents of the drive unit shown in FIG. 4 including a rim assemblycoupled via a gear assembly to one end of a rotor of an electric motorof the drive unit and with a brake rotor coupled to the other end of therotor.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described with reference to theaccompanying figures where like reference numbers correspond to likeelements.

A monorail train 2 comprises one or more monorail vehicles 4 whichtravel along a single rail 6, which acts as its sole support and itsguideway. This single rail 6 is also known as beam or track or guideway.

FIG. 1 shows the side view of a lead monorail vehicle 4 a and a partialview of a following monorail vehicle 4 b which is coupled to monorailvehicle 4 a in a manner known in the art to form monorail train 2. Othermonorail vehicles may be coupled in series to the end of vehicle 4 bopposite vehicle 4 a to form a monorail train of any suitable and/ordesirable length. Each vehicle 4 of train 2 receives electrical powervia dual third rails, contact wires or electrified channels 8 attachedto or enclosed in single rail 6.

With reference to FIG. 2 and with continuing reference to FIG. 1, eachmonorail vehicle 4 includes one or more drive units 10. Each drive unit10 is coupled to one or more drive wheels 12 which roll along a top partof single rail 6. Each drive unit 10 is coupled to a bogie 14 whichsupports drive unit 10 and drive wheels 12 in the manner discussedabove, and which also supports guide wheels 16 on opposite sides ofsingle rail 6. The number and physical arrangement of guide wheel 16 onopposite sides of single rail 6 can be selected in any suitable ordesirable manner by one of ordinary skill in the art. For example, inthe embodiment shown in FIG. 1, each bogie 14 supports three guidewheels on either side of single rail 6 in a T-arrangement, with twoguide wheels at the top of the T and a single guide wheel at the bottomof the T. The number and arrangement of guide wheels shown in FIG. 1,however, is not to be construed as limiting the invention in any manner.

With reference to FIG. 3 and with continuing reference to FIGS. 1 and 2,each monorail vehicle 4 has a body 18 which is supported by a frame 20to which each bogie 14 of vehicle 4 is coupled. Vehicle body 18 includesspaced sides 22, a passenger floor 24, and a roof 26. Each side 22 canoptionally include one or more windows 28 and one or more passengerdoors 30 that facilitate ingress and egress of passengers between theinside and outside of body 18. In one non-limiting embodiment, each door30 comprises one or more panels 32 which move in a first manner toreveal the opening between the interior and exterior of body 18 andwhich move in an opposite manner to close off the opening. In onenon-limiting embodiment, each panel 32 can be a so-called pocket doorwhich can slide between two wall panels of a side 22 to form thepassenger door opening and which can slide from between the two wallpanels to close off the passenger opening.

For the purpose of description, the length, height, and width (orside-to-side) direction or elongated vehicle body 18 can be consideredto correspond to X, Y and Z axes respectively of a Cartesian coordinatesystem. The X and Y axes define an imaginary plane that divides vehiclebody in half along the X direction. More desirably, the X and Y axesdefine an imaginary plane 34 that bisects the vehicle body 18 in half.The X and Z axes can be thought of as defining an imaginary plane 36extension (shown in phantom in FIG. 2) of passenger floor 24.

Drive unit 10 includes an AC electric motor 38 and a gear assembly 40that is coupled to each drive wheel 12. As shown in FIG. 2, electricmotor 38 is disposed in one of the halves of vehicle body 18 defined byimaginary plane 34. In addition, all or substantially all of gearassembly 40 is disposed in the same side of vehicle body 18 as ACelectric motor 38. In addition, at least portions of each drive wheel12, AC electric motor 38, and gear assembly 40 reside above imaginaryplane extension 36 of passenger floor 24.

As shown in FIGS. 2 and 3, because drive unit 10 can be placed all orsubstantially all in one of the halves (one side) of the vehicle definedby imaginary plane 34, wheels 12, and drive unit 10 can be covered by ashell 42 that is integral with one side 22 of vehicle body 18 (the leftside 22 in FIG. 2) but which defines a space 44 between the other side22 of vehicle body 18 (the right side 22 in FIG. 2) and the portions ofeach drive wheel 12, electric motor 38, and gear unit 40 residing aboveimaginary plane extension 36 of passenger floor 24. Stated differently,because of the arrangement of drive unit 10, bogie 14, and wheels 12, aportion of passenger floor 24 can be disposed between one side 22 ofvehicle body 18 (the right side in FIG. 2) and the portions of eachwheel 12, electric motor 38, and gear assembly 40 that reside above theimaginary plane extension 36 of passenger floor 24.

With reference to FIG. 4, as discussed above, drive unit 10 includes ACelectric motor 38 and gear assembly 40 received within a housing 46. ACelectric motor 38 includes a stator 48 and a permanent magnet rotorassembly 50. Stator 48 includes a magnetically susceptible core 52 andwindings 54 disposed on core 52 in a manner known in the art. Windings54 can be connected to a power convertor (not shown) disposed onmonorail vehicle 4 for controlling the supply of AC electrical power toAC electrical motor 38 in a manner known in the art to cause rotation ofpermanent magnet rotor assembly 50 in an appropriate rotationallydirection (clockwise and/or counterclockwise).

Permanent magnet rotor 50 includes one or more permanent magnets 56,desirably in place of rotor windings, to facilitate AC electric motor 38being lighter and smaller than a conventional AC motor while providing ahigher power output. In one non-limiting embodiment, AC electric motoris a 160 kw motor. However, this is not to be construed as limiting theinvention. Moreover, the description herein of AC electric motor 38having a permanent magnet rotor 50 is not to be construed in any manneras limiting the invention.

To maintain the compactness of drive unit 10, gear assembly 40 ispreferably a planetary gear assembly that includes a sun gear 58,coupled to one end of a drive shaft 60 of rotor assembly 50. Theplanetary gear assembly forming gear assembly 40 includes three or moreplanet gears 62 that surround and mesh with sun gear 58. A ring gear 64surrounds and meshes with planet gears 62. To facilitate rotation ofplanet gears 62 around sun gear 58 in response to rotation of sun gear58 by drive shaft 60 (in addition to rotation of each planet gear aroundits own rotation axis), planet gears 62 are held in fixed relation toeach other by a planet carrier assembly 66 comprised of a first part 66a and a second part 66 b on opposite sides of planet gears 62. Eachplanet gear 62 is coupled to planet carrier assembly 66 via a planetbearing ring 68 that enables the corresponding planet gear 62 to rotateabout its rotational axis during rotation of the entire planet carrierassembly 66 by sun gear 58.

A planet carrier bearing ring 70 supports planet carrier assembly 66 forrotation about sun gear 58 in response to rotation thereof. Desirably, arotational axis 86 of drive shaft 60 of AC electric motor 38, arotational axis 88 of sun gear 58 and a rotational axis of planetcarrier assembly 66 are coaxial.

Planet carrier assembly 66 also includes a hub connection housing 72coupled to first part 66 a of planet carrier assembly 66 for rotationwith planet carrier assembly 66 in response to rotation of sun gear 58by AC electric motor 38. A portion 74 of stationary housing 46 surroundsrotatable hub connection housing 72 of planet carrier assembly 66. Abearing ring (not shown) is disposed between portion 74 of stationaryhousing 46 and rotatable hub connection housing 72 to support therotation thereof in operation.

AC electric motor 38 includes cooling channels 76 disposed in one ormore stationary portions of AC electric motor 38. Each cooling channel76 is adapted to facilitate the flow of a cooling liquid therethroughwhereupon AC electric motor 38 can be liquid cooled.

With reference to FIG. 5 and with continuing reference to FIG. 4, asshown in FIG. 5, hub connection housing 72 of planet carrier assembly 66is coupled via bolts 78 to a hub 79 (or wheel flange) of a rim assembly80 that is coupled to the planet carrier gear assembly comprising gearassembly 40 for rotation thereby. Rim assembly 80 includes a pair ofside-by-side rim sections 82 a and 82 b adapted to support a pair ofdrive wheels 12 side-by-side for rotation about a rotation axis 84 ofrim assembly 80 that is disposed or runs coaxial with a rotation axis 86of rotor 60 and a rotation axis 88 of sun gear 58. As can be seen inFIG. 5, rotation axes 84, 86, and 88 are coaxial (or substantiallycoaxial). As can also be seen in FIG. 5, hub 79 extends radially fromrotation axis 84 of rim assembly 80 and terminates on an interiorsurface of rim assembly 80. Desirably, hub 79 extends radially fromrotation axis 84 of rim assembly 80 and terminates substantially at theintersection 90 of rim sections 82 a and 82 b. In FIG. 5, each rimsection 82 a and 82 b includes a portion of a drive wheel 12 (shown inphantom) on the bottom of said rim section to facilitate anunderstanding of the invention.

Because of the connection of hub 79 to hub connection housing 72 whichis coupled to the planetary gear assembly comprising gear assembly 40,drive shaft 60 rotating sun gear 58, planet gears 62 and hub connectionhousing 72 also rotates hub 79 and rim sections 82 a and 82 b about arotation axis 84 of rim assembly 80.

As can be seen in FIG. 5, rim section 82 a at least partially surroundsand will rotate about the planetary gear assembly that comprises gearassembly 40 in response to rotation of rim assembly 80 via gear assembly40.

With continuing reference to FIG. 5, a brake flange is coupled to an endof drive shaft 60 opposite gear assembly 40. In FIG. 5, sun gear 58 hasbeen omitted from rotor 60 for simplicity. A brake rotor 94 is coupledto brake flange 92. Brake rotor 94 can be utilized in combination withbrake pads (not shown) coupled to bogie 14 in a manner known in the artfor braking drive wheels 12.

As can be seen, disclosed is a compact drive unit 10 which can becoupled to a rim assembly, with a rotation axis of AC electric motor 38coaxial with a rotation axis of rim assembly 80. A gear assembly 40,desirably a planetary gear assembly, can be coupled between AC electricmotor 38 and rim assembly 80 with the rotation axis of the gear assembly40 coaxial with the rotation axes of AC electric motor 38 and rimassembly 80. The combination of the disclosed drive unit and thedisclosed rim assembly provides a compact arrangement for driving drivewheel 12 along rail 6. More specifically, the coaxial (or substantiallycoaxial) arrangement of the rotation axes 84, 86 and 88 of rim assembly80, drive shaft 60, and sun gear 58/planetary gear assembly avoidshaving to use a space consuming angled gear assembly arrangement tocouple an electric motor to a rim assembly with their respectiverotation axes disposed transverse or perpendicular to each other.

The present invention has been described with reference to theaccompanying figures. Obvious modifications and alterations will occurto others upon reading and understanding the preceding detaileddescription. It is intended that the invention be construed as includingall such modifications and alterations insofar as they come within thescope of the appended claims or the equivalents thereof.

The invention claimed is:
 1. A monorail vehicle comprising: a chassiscoupled to a body of the monorail vehicle; a drive unit coupled to thechassis, the drive unit comprising an electric motor and a planetarygear assembly rotatably coupled to the electric motor, the planetarygear assembly comprising at least 3 planet gears coupled between a sungear, which is coupled to a rotor of the electric motor, and a ring gearsurrounding the planet gears, the planet gears rotatable within the ringgear in response to rotation of the sun gear by the electric motor; anda rim assembly coupled to the planetary gear assembly for rotationthereby, the rim assembly including a pair of side-by-side rim sectionsadapted to support a pair of wheels side-by-side for rotation about arotation axis of the rim assembly that runs coaxial with a rotation axisof the rotor of the electric motor and a rotation axis of the sun gear,the rim assembly further including a hub that extends radially from therotation axis of the rim assembly and terminates on an interior surfaceof the rim assembly, wherein one of the rim sections at least partiallysurrounds and rotates about the planetary gear assembly in response torotation of the rim assembly by the planetary gear assembly.
 2. Thevehicle of claim 1, wherein the electric motor is an AC motor.
 3. Thevehicle of claim 2, wherein the AC motor is a permanent magnet AC motor.4. The vehicle of claim 3, wherein the permanent magnets are disposed onthe rotor.
 5. The vehicle of claim 1, wherein the hub terminates on theinterior surface of the rim assembly between the pair of side-by-siderim sections.
 6. The vehicle of claim 1, wherein the planetary gearassembly and the electric motor are received within a housing that iscoupled to the chassis, wherein the one rim section rotates about asection of the housing that houses the planetary gear assembly.
 7. Thevehicle of claim 1, further including a brake rotor coupled to an end ofthe rotor of the electric motor opposite the sun gear.
 8. The vehicle ofclaim 1, wherein an interior of the vehicle defines a passenger pathwaythat extends longitudinally along one side of the vehicle between aninterior surface of the vehicle body and the drive unit.
 9. The vehicleof claim 1, wherein the electric motor is received within a housing thatis coupled to the chassis, the housing including fluid channels adaptedto allow the passage of a cooling liquid therethrough for removal ofheat generated by the electric motor.
 10. A monorail vehicle comprising:a chassis supporting an elongated vehicle body that includes spacedsides and a passenger floor, wherein a length direction, a heightdirection and a width (or side-to-side) direction of the elongatedvehicle body correspond to X, Y and Z axes, respectively, of a Cartesiancoordinate system, wherein the X and Y axes define an imaginary planethat bisects the vehicle body in half; a drive unit coupled to thechassis, the drive unit comprising an electric motor and a gearassembly, the electric motor including a rotor that has an axis that isdisposed substantially parallel with the Z axis; and at least one drivewheel coupled to the rotor via the gear assembly, each drive wheelhaving a rotation axis that is disposed substantially coaxial with therotor axis, wherein the drive unit is supported by the chassis with theelectric motor and at least part of the gear assembly residing entirelyin one of the halves of the vehicle body with at least portions of eachdrive wheel, the electric motor and the gear assembly residing above aplane of the passenger floor of the vehicle body.
 11. The vehicle ofclaim 10, wherein a portion of the passenger floor is disposed betweenone side of the vehicle body and the portions of each wheel, theelectric motor and the gear assembly.
 12. The vehicle of claim 10,wherein the electric motor is a permanent magnet AC electric motor. 13.The vehicle of claim 10, wherein the electric motor is liquid cooled.14. The vehicle of claim 10, wherein the gear assembly is a planetarygear assembly.
 15. The vehicle of claim 14, wherein the planetary gearassembly has 3 planet gears coupled between a sun gear and a ring gearwhich surrounds the planet gears, wherein the sun gear is coupledbetween the rotor and the planet gears such that the planet gears arerotatable within the ring gear in response to rotation of the sun gearby the rotor.
 16. The vehicle of claim 10, further including a pair ofdrive wheels supported by a rim assembly which is coupled to the gearassembly by a hub of the rim assembly, wherein at least part of the rimassembly surrounds the gear assembly, which part of the rim assembly isrotatable about the gear assembly in response to rotation of the rimassembly by the motor via the gear assembly.
 17. The vehicle of claim16, wherein the pair of drive wheels have a common rotation axis, therim assembly includes a pair of rim sections with each rim sectionsupporting one of the drive wheels, and the rim assembly includes thehub which extends radially from the common rotation axis and whichterminates substantially at the intersection of the pair of rimsections.
 18. The vehicle of claim 10, wherein a bogie couples the driveunit and each drive wheel to the chassis.
 19. A monorail vehiclecomprising: a chassis supporting a vehicle body that includes apassenger floor and at least one side wall; an electrical motorsupported by the chassis; and a drive wheel coupled to a rotor of theelectric motor with a rotation axis of the drive wheel substantiallycoaxial with an axis of the rotor, wherein portions of the drive wheeland the electric motor are positioned on both sides of an imaginaryplane extension of the passenger floor.
 20. The vehicle of claim 19,further including a gear assembly coupled substantially coaxiallybetween the rotor and the drive wheel.
 21. The vehicle of claim 20,wherein the gear assembly is a planetary gear assembly that has arotational axis coaxial with the axis of the rotor and the rotation axisof the drive wheel.
 22. The vehicle of claim 20, wherein portions of thegear assembly are positioned on both sides of the imaginary planeextension of the passenger floor.
 23. The vehicle of claim 20, whereinthe passenger floor runs or extends between a front and a rear of thevehicle body and in a space between the drive wheel and the side wall.24. The vehicle of claim 19, wherein a bogie couples the electricalmotor and the drive wheel to the chassis.